To provide maximum benefit, an exercise machine should be designed not only to work specific muscle groups, but also to present a variable load that changes in proportion to the positionally related strength capability of the muscles being exercised. For example, it is now recognized that, in a rowing movement, the force capability of the normal subject will vary non-linearly from a maximum value, when the arms are fully extended, to a minimum value when they are withdrawn to a position close to his chest. Accordingly, it is desirable that any machine intended for the performance of such exercises be capable of offering a variable resistance that is closely correlated to the strength/position capacity of the involved muscle group.
In terms of absolute strength, it is also recognized that the range of normal capability is rather broad, and that some individuals are able to exert relatively high levels of force in such an exercise. Consequently, if the machine is to have widespread utility, it must, as a practical matter, be capable of multiplying the load of the attached weights. In addition, it is important that the machine operate smoothly and with a minimum amount of friction; otherwise, the purity or integrity of the exercise will be compromised by the introduction of spurious resistances, and the equipment will be subjected to excessive wear and inadequate durability.
Again, in more specific terms, a row machine will advantageously have the capacity of working all muscle groups through the back and shoulders, concentrating on the anterior deltoid, infraspinatus, rhomboideus, teres minor, teres major, latissimus dorsi and trapezius muscles. To do so, not only must the rowing motion be sufficiently sophisticated to kinesiologically correlate to the exercise, but the equipment must also accommodate gripping by the individual in different hand and arm positions, so as to effectively stress the various muscle groups. It is, of course, also of utmost importance that the equipment not cause undue stress upon vulnerable parts of the body, such as would create a risk of injury to the subject. As far as is known, no exercise machine heretofore described or provided offers the foregoing features and advantages.
Accordingly, it is a primary object of the present invention to provide a novel row machine, which presents a resistance to the subject that varies non-linearly throughout the range of movement that occurs during the exercise, and which is correlated to the normal strength-to-position relationship of the muscle groups involved.
It is also an object of the invention to provide such a machine which is effective to provide maximum exercise efficiency while avoiding overloading or underloading at any particular point during the range of movement involved in the exercise.
Another object of the invention is to provide such a novel machine which operates smoothly and with a minimum amount of friction, thereby affording maximum purity in the exercise while ensuring that the equipment will retain a high level of functional quality throughout a relatively long useful life.
Yet another object of the invention is to provide a machine having the foregoing advantages and features, in which the resistance offered is a multiple of the applied weight, to permit use by individuals representing a wide range of strength capabilities.
A further object of the invention is to provide a rowing exercise machine in which the subject is advantageously positioned for maximum benefit, while being protected against undue strain and injury, particularly to his lower back region.
A still further object of the invention is to provide a machine of the foregoing nature, in which various gripping positions are conveniently assumed, to thereby enable its use in exercising the various muscle groups of the back and shoulders.